The invention relates to a dosing device, especially for small-particulate pharmaceutical preparations, preparations in the form of pellets, granulates or extrudates, especially a drug dosing device, particularly with the features in the preamble of Claim 1, and furthermore, the use of a dosing device.
When compared with single-unit forms, e.g., tablets, small-particulate administration forms of pharmaceutical preparations, e.g., pellets, granulates or extrudates, exhibits advantages such as the small-particulate preparations providing a more even distribution in the intestinal tract, which is especially important for extended-release forms, and being easier to swallow, when administered as separate particles. Moreover, a single form of administration may cover a wider dosage range, whereby different amounts are filled into corresponding capsules and administered.
Usually, such small-particulate pharmaceutical preparations are filled into hard gelatin capsules, although these have a number of disadvantages when compared with the bulk product, i.e., small-particulate pharmaceutical preparations. Thus, the proportion of water of hard gelatin capsules must be greater or equal to 10 percent, otherwise, the hard gelatin capsules may embrittle and even break, while already in the packaging means or when removed therefrom. This may give rise to substantial packaging means problems for preparations sensitive to moisture, which often results in short shelf lives.
Since the relationship between the amount of preparation and the capsule shell varies for different doses, a separate extensive packaging means test must be performed for each dose.
Combining several small-particulate preparations is only possible to a certain extent, since the different dosages, i.e., the mix ratio between the individual preparations, is already predetermined. A conventional way of combining two active ingredients, whose individual components are present in two or three dosages, may require as much as six fixed drug combinations.
Prior art describes how to measure out with the aid of dosing devices a substantial amount of a small granular pharmaceutical preparation into a predetermined portion, which may then be given to a patient.
Thus, U.S. Pat. No. 4,805,811 and European patent EP-0 787 979 A1 each disclose a generic dosing device with a chamber for receiving a substantial amount of a small-granulate pharmaceutical preparation. A rotary valve incorporating several dosing chambers with preset volumes is provided on this dosing device. By turning the dosing valve about a vertically oriented axis, a partial amount of the preparation contained in the chamber is successively filled into one of the dosing chambers and re-emptied. The exit opening of the chambers filled with the preparation to be dosed and the ejection opening for the dosed preparation are arranged offset in axial direction relative to one another. Different dosages are obtained, whereby a corresponding number of partial amounts are removed from the chamber with the aid of the rotary valve.
These known dosing devices are especially designed to enable older persons and children or persons having difficulty swallowing larger tablets to measure out and ingest dosed amounts of small-particulate preparations that are easily swallowed.
European patent EP-0 217 390 A2, and French patents FR-2 380 536 and FR-2 380 537, each describe a dosing device provided with a chamber filled with a small-particulate pharmaceutical preparation allowing the removal of a defined, constant partial amount (dose) of the preparation from the chamber with the aid of a dosing chamber or dosing spiral formed on the valve.
Moreover, U.S. Pat. No. 4,273,254, British patent GB 1 316 174, U.S. Pat. No. 4,237,884, world patent WO 95/25050, or U.S. Pat. No. 5,255,786 describe so-called tablet separators, whereby several tablets are received in a chamber, from where they may be removed separately from the chamber, e.g., with the aid of a valve disk.
British patent GB 1 511 107 describes a measuring and dosing device for dosing granular alloys or metal, whereby the volume of a dosing chamber may be adjustable corresponding to a defined partial amount. For this purpose, a piston in a dosing valve is moveable and adjustable in preset positions by means of a wedge-shaped cam. Similar dosing devices are known from British patents GB 215 577 and GB 139 342.
Prior-art dosing devices are intended to dose the most varied preparations for all kinds of purposes. The design and configuration of the dosing device is subject to the consistency and properties of the preparation to be dosed. The described embodiments are thus characterized by a complex design, and sometimes complicated handling. Moreover, some of the devices are built very large due to the large distances that are inherently required between the feed opening from the chamber filled with the preparation to be dosed and the discharge opening for the dosed preparation, thus complicating handling precisely for the manual dosing of pharmaceutical preparations. This also applies to the structural implementation of different options that are sometimes provided for changing the volume of the dosing chamber and its motion between the filling and emptying position. For this purpose, regulating devices that are operated independently of one another are provided in order to adjust the dosage volume and the motion of the dosing chamber, whereby subsequent steps for resetting the dosing chamber are required, which steps are characterized by additional components and additionally required installation space. Automatic resetting is especially realized through operation against a pretension, for which corresponding means are again provided.